1st Avenue & I-80 Interchange

Coralville Diverging Diamond interchange rendering

Diverging Diamond Interchange
The Iowa Department of Transportation plans to reconstruct the interchange at I-80 exit 242 and 1st Avenue with a diverging diamond interchange (DDI). The Iowa DOT is the lead agency on this project.

Updates: Current & Upcoming Work
Major construction starts in mid-March and will reduce 1st Avenue to one lane in each direction over I-80 into fall 2024. Drivers should anticipate traffic delays and plan accordingly.

On 1st Avenue:
Between 9th Street and Holiday Road: 

  • March 20, 2023 through April 21, 2023*: 
    • Northbound and southbound traffic will shift to the west side of 1st Avenue across I-80 and will be one lane in each direction (head-to-head) through late 2024.
    • Northbound traffic on 1st Avenue that wants to head eastbound on I-80 will need to enter the right turn lane just north of the E. 9th Street intersection.  
    • All turns to and from the I-80 ramps will be open at all times. (See image below).

On I-80 westbound (Exit 242):
March 6, 2023-December 31, 2023*: Intermittent lane closures overnight between 7:00 pm and 6:00 am Monday through Thursday, and between 9:00 pm and 6:00 am Sunday.

On I-80 eastbound (Exit 242)*: 
March 6, 2023-December 31, 2023: Intermittent lane closures overnight between 7:00 pm and 6:00 am Monday through Thursday, and between 9:00 pm and 6:00 am Sunday.

*(Dates subject to change based on weather and unforeseen circumstances)

Comment: Davenport RCE (800-262-5145) 

Please check 511ia.org for the latest updates to the project.

Contact Us

  1. Iowa Department of Transportation

    Catherine Cutler
    Transportation Planner

    Iowa DOT logo

    City of Coralville

    Scott Larson
    City Engineer 

    1512 7th St.
    P.O. Box 5127
    Coralville, IA  52241

    Ph: 319.248.1720
    Fx: 319.248.1894
    Staff Directory

Traffic patterns starting March 20, 2023


Project at a Glance

The existing interchange at I-80 exit 242 is the original configuration constructed in the 1960s when I-80 was built through Iowa. The new diverging diamond interchange will provide safety improvements and is designed to handle projected traffic volumes. 

Major construction begins in mid-March 2023, and will reduce 1st Avenue to one lane in each direction over I-80. Once major construction begins, 1st Avenue will remain one lane in each direction over I-80 into fall 2024.

The prime contractor is Peterson Contractors, Inc., of Reinbeck, Iowa. The Iowa DOT is administering and inspecting the project.

Highlights Once Complete

  • Diverging diamond interchange design eliminates the left turn phase at signalized intersections. This reduces overall traffic delay while also providing a significant safety improvement since left-turning traffic is no longer crossing opposing traffic lanes.
  • New grade-separated trail with underpasses and a trail bridge over I-80.
  • New 1st Avenue bridges accommodate the potential future widening of I-80.
  • New, signalized intersection to serve Iowa River Landing Place and the Magellan Terminal. 
  • New stormwater management practices, traffic signals, roadway lighting, and aesthetic treatments. 

  1. Traffic & Pedestrian Impact
  2. Timeline
  3. Cost

Traffic & Pedestrian Impact

  • The project will utilize staged construction, including temporary pavement and temporary traffic signals. 
  • One lane of traffic will be maintained in each direction on 1st Avenue at all times.  
  •  Drivers should anticipate traffic delays and plan accordingly. 
  • After the 1st Avenue Trail closures in October and November 2022, pedestrian access along 1st Avenue over I-80 should not be impacted again for the remainder of the project.

Learn More
Iowa Department of Transportation
Iowa DOT project website

Watch Video: Navigating the Diverging Diamond Interchange

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